Achieving adequate air flow is essential to the operation of most modern vehicles, even those vehicles that do not utilize combustion engines, due to their reliance on heat exchangers. In general air, which is brought into the car via one or more air intakes, passes through one or more heat exchangers where the heat that has been generated by the various vehicle subsystems is transferred to the ambient environment. Depending upon the car's design, the air intake(s) as well as the heat exchanger(s) may be mounted in any of a variety of locations throughout the car, although typically the primary heat exchanger(s) is mounted at or near the front of the car where the primary air intake(s) is generally located. Common alternative air intake locations include the area between the rear of the hood and the windshield; behind the passenger cabin, e.g., the rear deck; and in front of either the front or rear wheel wells. The selection of the mounting locations for the various heat exchangers is often driven by vehicle packaging constraints as well as proximity to the heat source, i.e., engine/motor, battery pack, power electronics, transmission, etc. The heat exchanger(s) may be mounted directly behind the corresponding air intake, or located remotely from the intake and coupled together via ducting.
While the term “heat exchanger” refers to any type of device that transfers heat from one medium to another medium, vehicles predominantly use heat exchangers that transfer heat from a fluid, such as a coolant or a refrigerant, to air. The efficiency and performance of such a heat exchanger is primarily dependent upon the size of the heat exchanger, specifically the surface area of the heat exchanger, and the flow rate of each of the two mediums, i.e., the flow rate of the coolant/refrigerant as well as that of the air.
In order to achieve a high air flow rate as well as uniform flow distribution, a conventional vehicle utilizes an air intake that is of approximately the same size as that of the heat exchanger. Additionally, since most heat exchangers have an aspect ratio (i.e., height to width) that is in the range of 1:1 to 1:2 in order to provide a large surface area, the aspect ratio of the air intake in such a vehicle is also typically in this same range, i.e., 1:1-1:2. FIGS. 1 and 2 illustrate typical air intake configurations. Vehicles 100 and 200 utilize a heat exchanger 101 (e.g., dashed lines) with an aspect ratio of approximately 1:2. Air intake 103 is of approximately the same size and aspect ratio as heat exchanger 101, although intake 103 is shaped, e.g., rounded corners, for cosmetic and/or aerodynamic reasons. While vehicle 200 utilizes a pair of intakes 201 and 203, these two intakes are coupled to a single heat exchanger, i.e., heat exchanger 101, and perform as a single air intake system. FIG. 3 illustrates an alternate conventional air intake configuration. In this design a pair of smaller heat exchangers 301/302 is coupled via ducting 305 to a single air intake 303. Air intake 303 may or may not include a partition 307 that forcibly separates intake air into two air streams, one for either heat exchanger. In this configuration, the surface area of intake 303 is approximately equal to the combined surface areas of heat exchangers 301 and 302.
While the various air intake configurations used in conventional vehicles provide adequate air flow, given the limited aspect ratio range as well as the need to have an air intake of approximately the same size as the corresponding heat exchanger, the available options for possible intake designs is quite limited. This, in turn, limits the overall vehicle design, both in terms of cosmetics and vehicle aerodynamics. Accordingly, what is needed is an air intake system that provides the performance of a conventional intake without having the design limitations imposed by a conventional design. The present invention provides such an air intake system.